Tokyo: The use of around 1.63 million doses of Moderna Inc's Covid-19 vaccines has been suspended in Japan as a precaution following confirmation of presence of foreign materials in unused doses of the vaccine from the same production line, Japan's Health Ministry said on Thursday.
The Ministry said foreign substances were confirmed at eight vaccination centres in the prefectures of Ibaraki, Saitama, Tokyo, Gifu and Aichi on August 16, reports Xinhua news agency.
However, Japanese drugmaker Takeda Pharmaceutical Co., in charge of sales and distribution of Moderna vaccine in the country, said it has yet to see any reports of safety concerns and had reported them to the Ministry on Wednesday.
The size of foreign substances found in 39 vials is believed to be a few millimetres.
"To date, no safety or efficacy issues have been identified," Moderna said, adding it is "carefully assessing this matter and at this point does not have further comments on root causes".
The Ministry said the 1.63 million doses of Moderna vaccine were made in the same production line at the same time in Spain, and fall under three lot numbers -- 3004667, 3004734 and 3004956, which has already been handed out to 863 vaccination centres across the country.
The Ministry said it believes that although the risk of safety issues is "not significant", it will ask each facility that received the doses not to use them.
Over 10 million doses have already been used in the country since the Moderna vaccine accepted approval for emergency use in May, according to the government.
The Japanese government signed a contract with Moderna to receive 50 million doses of the vaccine by the end of September.
Currently people aged 12 and older can get shots of the vaccine.
Meanwhile, the Ministry revealed to public the lot numbers of the contaminated vaccines so that concerned individuals can check whether they received the potentially contaminated shots before the affected vaccine doses were suspended.
On similar abnormalities that may have been found in other countries, Moderna said it monitors and expeditiously assesses questions it received about the products from global markets, and local authorities will make their own decisions about disclosure of information following these assessments.
The report has come at a time when Japan is grappling with a Covid peak, and the the government declared a plan on Wednesday to put eight more prefectures under the state of emergency.